Distributed Privacy-Preserving Secondary Control for DC Microgrids via State Decomposition

In this article, a distributed secondary controller is proposed for an islanded DC microgrid to preserve privacy information of the local power sources, while achieving current sharing among the generators and voltage regulation of the DC bus. Based on the state decomposition mechanism, the original secondary control signal of each generator is decomposed into two parts: one takes over the role of communicating with neighbors, while the other affects the evolution of the former one and is invisible to the neighbors. Besides, random noises are introduced to mask the true value of the transmitted signals. Under the proposed controller, the current data of the local generators can be kept confidential, as well as the associated privacy power information. In this way, the power security risks caused by privacy information leakage can be avoided. Lastly, both simulation and experiment tests are imposed to verify the effectiveness of the proposed control scheme.